[Ecological economic analysis of a rice-crab model].

Based on field investigation and experimental data analysis, ecological economic principles were applied to study the structure and function, the characteristics of material and energy flows, and the economic and ecological benefits of a rice-crab model. The results show that rice-crab model had a higher integral benefit than rice model, and its net income, cost-benefit ratio, and labor productivity were increased by 382%, 67.7% and 295%, respectively. In view of the ecological benefits produced, the total nitrogen, alkaline-hydrolyzal nitrogen, total phosphorus, rapidly available phosphorus, rapidly available potassium, and organic matter in the soil after 1-year carb breeding were increased by 10.6%, 3.3%, 5.8%, 11.7%, 3.5% and 10.5%, respectively. Moreover, 6.375 kg N.hm-2 of non-point source pollution load could be cut down annually.